Stuttering Research Commentary #1 by HCRI

There is no doubt that stuttering is associated with specific forms of brain activity. In fact, all human behavior is mediated by brain functioning of one type or another. When we learn something new — a fact, a poem, a song or a motor skill — we do so because we have experienced reorganization of brain function.

As research scientists focus on determining the cause of stuttering, it is important to examine how the brain is involved in stuttering. Yet, it is premature to rush to the simple conclusion that the brain is “causing” stuttering.

The brain operates as a complex set of physiological systems that are, in turn, provided with an array of inputs and outputs. The research task is to develop an understanding of the complex context within which the brain functions.

The following research abstract is the first of a series provided as a service by Hollins Communications Research Institute (HCRI).  HCRI is a nonprofit Institute based in Roanoke, Virginia that has been at the forefront of stuttering research and treatment innovation since 1972.

HCRI commentary follows the abstract and is provided Ronald L. Webster, Ph.D., HCRI’s Founder and Director.

ABSTRACT: A positron emission tomography study of short- and long-term treatment effects on functional brain activation in adults who stutter.

J Fluency Disord. 2003 Winter;28(4):357-79; quiz 379-80., e Nil LF, Kroll RM, Lafaille SJ, Houle S., Graduate Department of Speech-Language Pathology, University of Toronto, Ont., Canada M5G 1V7.

Educational Objectives:

1. Use of functional neuroimaging PET in the study of stuttering;
2. Differences in neural activation between stuttering and non-stuttering adults; and
3. Effects of behavioral fluency treatment on cortical and subcortical activations in stuttering speakers.


Previous studies have shown that fluency-inducing techniques, such as choral speech, result in changes in neural activation as measured by functional neuroimaging.

In the present study, positron emission tomography was used to investigate the effects of intensive behavioral treatment, followed by a 1-year maintenance program, on the pattern of cortical and subcortical activation in stuttering adults during silent and oral reading of single words.

The results indicate changes in activation lateralisation, as well as a general reduction in over-activation, especially in the motor cortex, following treatment. The results are discussed in light of previous functional imaging studies with stuttering adults.

HCRI Comment:

This article illustrates clearly that differential brain function is seen in stutterers before and after participation in a therapy derived from one of our earlier therapy systems. The essential point is that post-treatment, brain activity in stutterers was closely similar to the brain activity of fluent speakers.

For more information about HCRI’s work in the field of stuttering and treatment programs, visit .

HCRI: Driven By Research

Hollins Communications Research Institute
Driven By Research

HCRI is a pioneering institution in the continued development of research based, behaviorally oriented stuttering therapy. Our long term research on the observable features of stuttered speech has provided a strong foundation for development of practical and effective treatment programs for stuttering, including the Precision Fluency Shaping Program, and the more advanced and recent stuttering therapy program, the Hollins Fluency System™

HCRI has been a leader in the comprehensive behavior analysis of stuttered speech. We have identified a series of “fluency targets” involving articulation, voicing and respiration that can replace the distorted motor events of stuttered speech.

HCRI has also devoted work to developing specific methods of training within our therapy program. We have learned which training sequences are maximally effective and what skill levels must be attained within each step of the therapy process in order for success to follow at the next step. Laboratory derived principles of learning have been applied throughout the therapy program in order to foster effective acquisition and long term retention of fluency.

Our research has shown that the cognitive and emotional components of stuttering result directly from the presence of disturbed speech muscle movement patterns. This research has enabled us to develop methods of therapy that deal in a balanced manner with the motor, cognitive and emotional aspects of stuttering.

Research conducted at HCRI has permitted us to develop electronically based measurements of fluency skills. With our computerized instrumentation, we can measure a person’s progress through important stages within the therapy process. Our devices allow each person in therapy to receive immediate, precise feedback about the accuracy of performance on specific fluency targets. This advanced method of training within therapy provides each person with explicit knowledge of what must be done to generate fluent speech.

Additional research projects at HCRI deal with the role of sensory feedback in speech motor guidance, the detailed analysis of how stuttering is organized, and the development of improved fluency target measurement systems.

HCRI’s research continues with long-term monitoring of clients after therapy. This work helps us better define the relationships between fluency targets, training methods and the retention of fluency skills. It also guides us in making small, but important improvements within the therapy program.

Our Staff
HCRI’s staff consists of full-time clinicians, researchers and support personnel who specialize in the treatment of stuttering and in research on stuttering. Clinical staff members hold advanced credentials and have extensive experience in working with all levels of stuttering severity. Click Here to meet our staff.

View the videos at the left in order to learn more about how HCRI is advancing the understanding of stuttering and the ability to treat it effectively. This special therapy is only available at HCRI in Roanoke, Virginia USA. To receive more information by mail about HCRI’s stuttering therapy,Click Here